The present disclosure pertains to an aqueous pigment dispersion containing a hydroxyl-substituted amino acid, a dispersant, and a pigment colorant. The present disclosure further pertains to an ink and an ink set containing the aqueous pigment dispersion, and printing of said ink on a variety of substrates, particularly nonporous media.
Digital printing methods such as inkjet printing are becoming increasingly important for markets other than conventional desktop printing for small office/home office. The desktop printing market category is based upon the use of inks that have been optimized primarily for printing documents and photographs. Commercial printing applications range from printing wide format posters, banners, and billboards, to product coding on cans and bottles. For this disclosure, printing of wide format graphics is considered as commercial printing. Industrial printing applications include direct mail, addressing, product coding, and marking. High speed, page wide array industrial inkjet-based printers are also used to print magazines and newspapers, etc. In addition, a new field in commercial printing is printing of books on demand in a bookstore setting.
The inks used in commercial/industrial applications often have different requirements. For conventional desktop printing, print droplets must be tightly controlled. Additionally, desktop printers print on limited types of substrates. For commercial and industrial printers, a high premium is place on being able to print on a wide range of substrates. Industrial inkjet printing is an established and expanding market. Inkjet printers are widely used to place images on mail and business forms, on primary and secondary packaging. Also, the time for the printed image to dry is much more important for commercial/industrial printing.
The substrates for commercial/industrial printing range from porous substrate like newspaper media, uncoated bond papers used to print books and transpromotional material to nonporous media used to print magazines and marketing literature. Furthermore, home/office paper may be printed as well.
Ink viscosity is a critical attribute for an ink impacting the ink's jetting reliability. Additives are known to be included in an ink to modestly change its viscosity to satisfy requirements for printheads and other printing factors. Such ink viscosity additives should not affect other ink properties such as conductivity and stability. A need exists for new viscosity modifiers with improved properties. These viscosity modifiers may be added during preparation of aqueous pigment dispersions prior to formulation of inks. A need also exists for highly stable, higher-quality and different property inks for ink-jet applications.